> Only an encrypted blind relay to allow for shared editing. The relay doesn't see any of the data.

Would love to know more about how this works then? Is it more or less encrypted P2P?

This doc goes into more detail -

https://github.com/nyblnet/bento/blob/main/docs/security.md

But basically when your bento HTML first gets saved, it generates a number of keys used for managing the permissions to join the Cloudflare DO. You can then send out an invite deck with a key that allow other people to join (with their own generated keys). With this architecture, you can revoke people's access, as well as giving them only read-access to the sharing session for example.